A) Field of the Invention
The present invention relates to a method of assembling a clutch disc subassembly using a friction facing alignment jig, and further to configuration of friction facings and a cushioning plate of a clutch disc subassembly.
B) Description of Related Art
In one type of clutch disc assembly, the construction includes a clutch disc main body and a subassembly concentrically joined to the clutch disc main body, functioning to engage frictionally an engine flywheel with a clutch pressure plate. The clutch disc main body incorporates a damper for dampening shock caused as the clutch is engaged, as well as spurious torsional vibrations during power transmission by the clutch. The clutch disc subassembly includes a cushioning plate peripherally fixed to the clutch disc main body, and friction facings fixed by rivets to opposite radially extending sides of the cushioning plate.
The frictionally engaging clutch disc subassembly, when pressed by a pressure plate against an engine flywheel, functions to transmit torque from the flywheel to the clutch disc. As the clutch disc subassembly is urged into contact against the flywheel, the cushioning plate deforms elastically, absorbing engagement shock.
In assembling the disc subassembly for the conventional clutch disc as stated above, the cushioning plate is first fixed to a clutch plate assembly of the clutch disc by rivets. One of the pair of friction facings is then fixed to one of the radially extending sides of the cushioning plate by rivets, whereupon the second of the friction facings pair is riveted onto the opposite radially extending side. Herein, there may be no direct coordination between the steps of mounting the one and the other of the friction facings onto the opposite radially extending sides of the cushioning plate. Consequently, the friction facings sandwiching the cushioning plate in the assembled clutch disc are not likely to be perfectly paired, but rather may be out of alignment with respect to each other. Of particular concern is radial misalignment of the opposed friction facings, whereby there is significant disparity in the moment arms of the opposite radially extending sides of the cushioning plate.
Accordingly, unless an operator intervenes in the assembling process to check and ensure proper alignment of the respective components that make up the clutch disc subassembly, the clutch disc will rotate out of balance, and vibrations will develop in the operational friction engaging subassembly as well The need for operator intervention has impeded automation of the entire clutch disc assembling process.